Essentially, Onecut1 is critical for the formation of horizontal cells, but of fundamental importance to retinal degenerative research, this work implies that horizontal cells might be necessary for the survival of photoreceptor cells. Of course we have known for some years that horizontal cells are some of the very first cells to respond to retinal degeneration by extensively remodeling, but this is an interesting result that suggests a direct dependence of photoreceptors on the horizontal cells themselves for survival.